The 27-tonne Soviet Tsar Bomba (king of bombs) was the most
powerful weapon constructed.

Officially named AN602 hydrogen bomb, it was originally intended
to have a yield of 100 megatons, but this would have posed problems with
the radioactive fallout.

Later, the Tsar Bomba was reduced to have a yield of only 50 megatons of
TNT.

In an atmospheric test in 1961 it had a yield of 50 megatons -
3,300 times as powerful as the Hiroshima bomb and 1,400 times as powerful as the Hiroshima and Nagasaki
nuclear bombs combined.

The bomb served no military purposes. For that, it would be too
heavy to carry and there was no plane able to do intercontinental flights with such a
load.

History of
development

The idea of creating a bomb of
this power first appeared on July 10 1961 in a meeting between
Khrushchev and the senior weapon designer, Andrei
Sakharov. Initially, the bomb should have had a yield of 100
megatons, but this was changed in a later stage since a bomb that
big would have posed serious safety issues and it would have affected
inhabited parts of northern Soviet Union.

The development of the Tsar
Bomba was rushed, since Nikita Khrushchev wanted the bomb to be
detonated during the 22nd Congress of the Communist Party held between
October 17 and October 31 1961.The
development team consisting of Victor Adamskii, Yuri Babaev, Yuri
Smirnov and Yuri Trutnev had little time to prepare the bomb so they
rushed everything.

Assembly was carried out in parallel with designing. The design of
the bomb posed serious questions. Its weight of 27 tones was two and a half times the Tu-95's normal weapon
loads and close to the plane’s total weightload. Since the Tsar Bomba was too big, the Tu-95 had to be
slightly modified; the bomb doors had to be removed.

Also a custom parachute had to be built in order to slow the bomb’s
descent so that the plane has enough time to get to a safe place.

Detonation

The plane piloted by Andrei Durnovtsev dropped the Tsar Bomba at 11:32 AM Moscow
time, from a height of 6.5 miles (10.5 km) over Mityushikha Bay in Novaya Zemlya. The bomb detonated at a
height of 2.5 miles (4 km). The descent from the height it was dropped from until the place of the
detonation at 4,000 meters above ground took 188 seconds, just enough time for the pilot, Andrei Durnovtsev
to fly to a safe distance. Just one second after the detonation, the fireball was already 4 miles wide, and
the light could be seen at distances of over 2,000 kilometers. The mushroom raised to a height of
about 64 km, over 7 times the height of Mount Everest.

In the video section of this site you can see some videos made during the detonation,
and on the Map section you can see where exactly the ground zero is, as well as the route of the
plane.

Aftermath

After the explosion, the surface of the island was leveled, and the rocks
melted. Some reports indicate that windows were broken in northern Finland and Norway too.

Amid concerns about radioactive fallout, in 1963 the US, UK and USSR
signed the Partial Test Ban Treaty forcing all nuclear tests to be underground.